Free resources · Dosage calculations
Weight-based doses
Doses ordered per kilogram, including converting a weight given in pounds.
Worked example: learn the method
Ungraded teaching example with different numbers from the practice exercise. For study only, not clinical use.
A dose is ordered at 5 mg/kg. The person weighs 26 lb. What total dose does that order call for?
Weight in kg × dose per kg = total dose (lb ÷ 2.2 = kg)
- Convert pounds to kilograms: 26 lb ÷ 2.2 = 11.82 kg
- Multiply by the ordered dose: 11.82 kg × 5 mg/kg = 59.09 mg
- Units cancel: kg × (mg/kg) leaves mg — the unit the order is written in.
Example result: 59.1 mg. Round the dose to the nearest tenth of a milligram.
Common mistake to avoid: Convert pounds to kilograms first when the exercise requires it. Distinguish a dose per day from a dose per administration.
Dosage formulas · Unit conversion reference
Problem
A dose is ordered at 5 mg/kg. The person weighs 78 lb. What total dose does that order call for?
Round the dose to the nearest tenth of a milligram.
These are practice problems for exam preparation. Every number in them is generated by CARE for teaching purposes — nothing here is a real order and nothing here is a clinical dosing tool. Do not use this page to work out a dose for a real patient: use your facility's policy, the actual order, and an independent double-check where your policy requires one.
Medication calculations also appear inside real exam practice, mixed with everything else and scored the same way. Try a free quiz drawn from the actual question bank.
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